1. Field of the Invention
The present invention relates to communication control systems using an Asynchronous Transfer Mode (ATM) Network and more particularly to a communication control system using an ATM network, which is constructed by a small number of virtual connections.
2. Description of the Related Art
FIG. 13 shows a conventional communication control system using an ATM network. The ATM network system of FIG. 13 includes six user interfaces IMF1-IMF6 which are connected to the corresponding groups of user units E11-E1m, E21-E2n, E31-E3o, E41-E4p, E51-E5q, and E61-E6r. The user interfaces IF1-IF6 are connected to an ATM network 10, which have many fixed or semi-fixed virtual connections 11 which interconnect user interfaces IF1-IF6 in a mesh-like manner.
In such an arrangement, user interfaces IF1-IF6 convert data packets outputted by user units E11-E1m, E21-E2n, E31-E3o, E41-E4p, E51-E5q, and E61-E6r to ATM cells and deliver the converted ATM cells to virtual connections 11 connected to a destination user interface.
However, this conventional system requires the virtual connections whose number is given by EQU N.times.(N-1)/2
where N is the number of user interfaces. Thus, as the scale of the system becomes large, a great number of virtual connections is required. Such system is not practical.